1. Field of the Invention
The invention relates to a lift for skids and pallets.
2. Description of the Prior Art
Skids and pallets provide a relatively flat and stable platform on which to stack loads for transport.
A skid consists of three parallel wooden beams running lengthwise of the skid and a series of parallel wooden boards running widthwise of the skid. Each of the beams has a lower edge on which the respective beam rests when the skid is on the ground, and each of the beams further has an upper edge to which the boards are secured. Neighboring boards are spaced from one another by a predetermined distance, and the boards cooperate to define a platform for a load. Neighboring ones of the beams are spaced from each other by a distance greater than that between the boards, and the beams define two passages running lengthwise of the skid.
Similarly to a skid, a pallet has three lengthwise beams as well as a series of boards that are located on the upper side of the pallet and define a platform for a load. However, in contrast to a skid, a pallet is provided with several boards also on the lower side thereof. These lower boards again run widthwise of the pallet, and one lower board is situated at either end of the pallet while one or more lower boards is disposed at or near the middle of the pallet. The lower boards rest on the ground when the pallet is set down. As in a skid, the beams of a pallet define two passages running lengthwise of the pallet, and such passages extend between the upper and lower boards.
A device capable of lifting and transporting both skids and pallets is the forklift. This is a motorized vehicle having a pair of spaced prongs or tines that project to the front of the vehicle and are movable up-and-down on a mast or column. To lift a skid or pallet, the prongs are aligned with and are inserted lengthwise in the passages of the skid or pallet. After the prongs have been inserted in the passages, the prongs are raised to lift the skid or pallet off the ground for transport. The range of motion of the prongs is sufficient to lift a skid or pallet to a so-called “work height,” which is typically 30 inches.
Since forklifts are expensive, a cheaper alternative known as a manual stacker is frequently employed. As opposed to a forklift, a manual stacker is not motorized and is propelled manually. Similarly to a forklift, a stacker has a pair of spaced prongs or tines that project to the front of the stacker and are movable up-and-down on a mast or column. A stacker additionally has a pair of so-called outriggers projecting to the front of the stacker in the form of beams with wheels or casters at the forward ends thereof. The outriggers, which are spaced from each other widthwise of the stacker and prevent the stacker from tipping forward under the weight of a pallet carried by the prongs, are not required on a forklift because the motor that propels the forklift is rear-mounted and serves as a counterweight to the pallet supported by the prongs. Such a counterweight is lacking on the non-motorized stacker. Like the prongs of a forklift, the prongs of a stacker have a range of motion sufficient to lift a skid or pallet to the working height.
The distance between the prongs of a stacker is less than the width of a pallet in order to allow the prongs to enter lengthwise the passages of the pallet. On the other hand, the outriggers of a stacker are spaced from each other by a distance greater than the width of the pallet so that the pallet can fit between the outriggers. If the spacing between the outriggers were less than the width of the pallet to thereby allow the outriggers to enter the passages of the pallet lengthwise, the lower boards of the pallet would lie underneath the outriggers and prevent the prongs from lifting the pallet. This problem does not arise with skids that do not have lower boards. However, due to the large spacing between the outriggers of stackers, they are difficult to maneuver.
A manually propelled device structurally similar to a stacker is the skid lift. The main difference between a stacker and a skid lift is that the outriggers of a skid lift are spaced from one another by a much smaller distance than the outriggers of a stacker. Typically, the distance between the outriggers of a skid lift is about equal to the distance between the prongs of the skid lift. Consequently, the skid lift is considerably narrower and easier to maneuver than a stacker. However, a skid lift cannot be used for pallets because its outriggers enter the passages of the pallet lengthwise and thereby prevent the prongs of the skid lift from raising the pallet.
Another manually propelled device is the pallet truck or pallet jack which, unlike the skid lift, can be used for both pallets and skids. A pallet truck has a pair of prongs with wheels designed to enter the passages of a pallet or skid lengthwise. In order to raise the pallet or skid off the ground, the wheels of the prongs can be moved between retracted and extended positions. When the wheels are retracted, the prongs are in a lowered position and can enter the passages of the pallet or skid lengthwise. The wheels still contact the ground while retracted and, in the case of a pallet, roll over the lower boards of the pallet upon entering the passages of the pallet lengthwise. Once the prongs have been properly positioned lengthwise in the passages of the pallet or skid, the wheels are extended thereby raising the prongs and lifting the pallet or skid off the ground for transport.
Although pallet trucks are easy to maneuver and operate and are therefore quite popular, they are incapable of lifting a pallet or skid to a working height. Therefore, there is still a need for an improved manually operated device that allows both transport and lifting of a pallet or skid to a working height.